If you know anything about me, you'd be aware that I haven't touched Windows in three years. But if I had to use a GPS navigation device for driving, and if (hypothetically) TomTom only supported Windows, I would would be willing to add a partition for Windows. I have had several Garmin units while on holiday or business travel, on three different continents, and I must say it's quite pathetic. In the US sent me the wrong direction so many times, I stopped using it (with 3000 miles left to drive through parts unknown) - I had better luck trusting my gut. In december I had a rental car while in CT to attend a friend's wedding. Well, despite leaving with enough time to be an hour early, I was later than the bride. Thank you Garmin. On the same trip, I decided to drive from Gansbaai (where we stopped over for few days) to Cape Agulhas, and the POS took me over gravel road after gravel road, despite setting it to avoid unpaved roads. Needless to say, I drove back on gut feeling only (I've never been in the area before) and made it back in half the time it took me to get there.
By contrast, I've had none of this nonsense with TomTom units. Sure, I've seen it missing some streets that I know are there, or taking routes that I wouldn't consider the best, but I've never had it violate my trust in the way that Garmin does just about every time I have to use one.